If you’re used to traveling around Europe, this news won’t come as any surprise—yet another strike affecting air travel is looming. This time, it’s potentially a big one: workers at 46 airports across Spain have voted for a general strike to protest what they say are poor working conditions and low pay.

Slated to begin this month, the workers said they will stage a series of one-day walk-outs over a three-and-a-half month period, timed for maximum effect over weekends and holidays. The job action will affect everything from baggage handling, security, airport concessions, catering operations, parking lots, information, and other facilities. In all, the unions backing the move have targeted some two dozen dates that appear designed to inflict maximum pain on Spain’s thriving tourism business, including Fridays and Sundays in September, October, and November, and the week of December 26 through 30.

Asked whether the airports had any contingency plans to deal with the potential disruption, Aena, the Spanish airport operator, said it’s too early to predict whether the walk-out will actually occur. “The strike is only announced, it is not called yet,” a spokesman tells Condé Nast Traveler. And a representative for flag carrier Iberia expressed optimism that ongoing talks between the government’s Infrastructure Ministry and the unions would head off the strike. (Strikes were originally supposed to begin on September 15, but there is hope that the results of a September 7 meeting between the unions and airport operators will prevent the strikes.)

So why is this happening now? For one, airline and airport employee walk-outs are increasingly commonplace in Europe, where unions enjoy stronger protections than their stateside counterparts. Earlier this year, nearly all flights in and out of Berlin were halted during a one-day strike at Berlin’s two working airports, and across the continent, aviation workers ranging from air traffic controllers to pilots, have taken turns walking off the job. In Spain, Barcelona’s El Prat Airport was already the target of one such action in August, when security staff went on strike.

Airport workers’ discontent isn’t confined to Europe, of course. In the U.S., several unions representing airport employees have called strikes in the past year to call attention to their plight, most recently, in mid-July, when staff at New York City’s two main airports, LaGuardia and JFK, called a strike to draw attention to what they said were below-market wages and unfair labor practices. (Workers returned to their jobs within hours, however, after the parties agreed to return to the bargaining table.) Last summer, workers at Philadelphia Airport also staged a similar protest in advance of the Democratic National Convention; and last year, airport contract workers also walked off the job at Chicago O’Hare.

Both here and abroad, the protests raise a similar concern: while air travel is booming, airport workers seem to be stuck in a holding pattern. Part of the problem is that often these workers don’t work directly for the airlines or the airports, which usually contract out these services to companies that have a strong incentive to offer the lowest bid—and thus hold down wages. As the union representing the New York workers said, “While the airlines have been making record profits…the airport workers who make these profits possible are struggling to survive."